1. Field of the Invention
The present invention relates to rail guided vehicles and, more particularly, to guide wheels for guide frames of rail guided vehicles.
2. Description of the Prior Art
Rail guided vehicles typically include one or more guide frames that cooperate with, or xe2x80x9cfollowxe2x80x9d, a guide rail to steer the vehicle. Typical prior art rail guided vehicles include people movers, light rail vehicles and land vehicles such as buses. Multiple guide wheels attached to the guide frame of the vehicle provide the physical interface between the vehicle and the guide rail.
In general, prior art guide wheels include a fixed portion connected to a rotating portion by a bearing. The fixed portion is generally attached to the guide frame of the vehicle. The bearing generally serves to secure the rotating portion to the fixed portion and support the rotating portion in the vertical direction. Prior art guide wheels suffer from the disadvantage that in the event of failure of the bearing, the rotating portion may separate from the fixed portion and fall onto the roadway or the rail bed along which the vehicle travels. This debris is a hazard to following vehicles and, in particular, could potentially cause a derailment of following railway vehicles. Furthermore, the loss of one or more guide wheels in this manner also means loss of guidance for the vehicle, which could result in a derailment of the vehicle and injury to the occupants of the vehicle.
In addition, prior art guide wheels typically cannot be easily pre-assembled and attached to the guide frame of the vehicle. The fixed portion of the guide wheel must first be attached to the guide frame of the vehicle. Next, the rotating portion must be mounted to the fixed portion by the bearing.
Consequently, a need exists for a safer alternative to the guide wheels currently used in the art. In addition, a need exists for guide wheels that are simpler to install and maintain than the guide wheels currently known in the art.
Therefore, it is an object of the present invention to provide a guide wheel assembly having improved safety characteristics. In addition, it is an object of the present invention to provide a guide wheel assembly that can be easily pre-assembled and attached to a guide frame of a rail guided vehicle. Furthermore, it is an object of the present invention to provide a guide wheel assembly having improved installation and maintenance characteristics.
The above objects are accomplished with a guide wheel assembly made in accordance with the present invention. The guide wheel assembly is generally attached to a guide frame of a rail guided vehicle. The guide wheel assembly includes a shaft having a first end and a second end. The shaft has an integrally formed flange located adjacent the second end of the shaft. A sleeve is positioned about the shaft. The sleeve has a first end face and a second end face. The first end face is configured for attachment to the guide frame of the rail guided vehicle. A bearing is positioned rotatably about the shaft and located axially between the flange and the second face of the sleeve. A rotating assembly is positioned about the bearing and coupled to the shaft by the bearing. The rotating assembly is configured to cooperate with a vertical guide rail configured to guide the rail guided vehicle laterally. The rotating assembly further includes a hub having an integrally formed and radially extending safety disc with two faces and a pair of rims each having a guide tire connected thereto. The rims are connected respectively to the two faces of the safety disc. The guide tires are configured to engage the vertical guide rail. The safety disc at least partially extends between the guide tires such that in an event of failure of the guide tires the safety disc limits lateral movement of the guide tires with respect to the guide rail. Furthermore, a support member, such as a washer, is preferably welded to the second end of the shaft for supporting the bearing and the rotating component in a vertical direction in the event of failure of the bearing.
The guide wheel assembly may include a dust cover positioned about the sleeve and extending between the sleeve and the hub for preventing dirt from entering the bearing. The guide wheel assembly may further include a snap ring positioned about the flange and configured to secure the bearing to the hub. The first end face of the sleeve may be formed as a connecting flange defining a bolt circle such that the guide wheel assembly is connectable to the guide frame of the rail guided vehicle with a plurality of bolts cooperating with the bolt circle. The bolt circle may have a centerline coextensive with a central axis of the shaft. Alternatively, the centerline of the bolt circle may be offset radially from the central axis of the shaft. The bearing is preferably a UNIPAC(copyright) sealed and greased double row tapered roller bearing.
A method of assembling a guide wheel assembly configured for attachment to the guide frame of the rail guided vehicle is also part of the present invention. Further details and advantages of the present invention will become apparent from the following detailed description, in conjunction with the drawings.